1. Field of the Invention
The present invention relates to a server system and methods for conforming to different protocols. More particularly, the server system and methods for adapting to various protocol formulas in case of sending out large quantities of continuous and consecutive data such as audio data of moving images and voices on a communication line.
2. Description of the Prior Art
It is necessary for sending and receiving-of data via such communication lines as the Ethernet to generate and analyze communication data conforming to different protocols. Furthermore, in transferring a large volume of data such as moving images at a high speed, it is important to speed up the protocol adapting process.
FIG. 12 shows the conventional protocol-conforming process in the server system.
In the prior art, a server system 608 is connected to a terminal unit 607 via a communication line switch 606. According to the instructions from a central control 605, a protocol sender-receiver 604 makes a processing to send or receive the communication data.
When the server sends out the data to the terminal unit in response to a demand for data from a terminal unit, at first, the central control 605 prepares header information for the communication such as data to communicate, and the addresses of the terminal units on the communication lines, and further, stores them in a header memory 602 and in a contents memory 603 respectively.
According to instructions from the central control 605, a protocol separator-coupler 601 reads out the header from the header memory 602 and the contents from the contents memory 603, and then couples the header and the contents, and thereafter generates a packet data adapted to the form of the communication protocol, which data is sent to the protocol sender-receiver 604. The central control 605 instructs the protocol sender-receiver 604 to send out the data, and the data are sent to the terminal unit 607.
The above mentioned header has different standards based on communication systems, e.g., TCP/IP for the Internet, IPX standard of Novell Inc., a data transfer system of NFS protocol, and data transfer system of "endless effluence" style, etc. The communication system comprises the signal to designate its communication style in response to the request-to-send of the terminal unit. After reading out the signal, the central control 605 prepares the header applicable to the demand from the terminal unit.
On the other hand, in case of receiving data from the terminal unit 607, a packet data is first received by the protocol sender-receiver 604 via network. The said protocol sender-receiver 604 transfers the received packet data to the protocol separator-coupler 601, where the data is separated into the header and the contents. The header obtained as mentioned above is stored in the header memory 602 temporarily, while the contents is kept in the contents memory 603 in the same way. In the next step, the central control 605 will make the necessary processing as writing into the hard disk the contents equivalent to the information (file name, packet number, data size etc.) stored in the header memory 602 or making the data shown on the display.
However, in the foregoing protocol processing in the prior art, the central control 605 makes the necessary processing including the generation of a header for communication to the terminal unit and giving instructions to couple data. As described above, demands from the terminal unit are not simple, so that the central control 605 often has to prepare many headers in response to various demands. And also, the amount of that processing or workload get to be increased, and its takes much time. This system processes not only send protocols but also receive protocols, which adds the further load on the central control 605.
Therefore, it takes a longer time, to send data equivalent to a request-to-send from the terminal unit 607 in response to the said request-to-send, and it delays sending data to the terminal units. Especially in each time of sending out running data such as moving images or pictures, data is fragmented into packet data in the same size and formed the same header. The protocol processing, that is, coupling the header with data and sending out the same is repeated, so that it results some defaults, that is, the overhead increases, the sending out from the server is delayed, and the reproduction of moving images on the terminal side is disrupted.
The present invention is proposed based on those shortcomings of the prior art.